There are a wide variety of infant oral feeding bottles on the market. In general, their components comprise a feed container, which is usually transparent and made of glass or plastics material, the container having at its open end a neck to which is releasably connected a feed dispensing means, usually a teat, formed of rubber or plastics material. The feed container is usually provided with a screw thread about its neck, and a threaded retaining collar is used to connect the feed dispensing means to the container.
Other components which can form part of a conventional infant oral feeding bottle include a sealing disc, which is used to cover the open end of the feed container when the feeding bottle is not in use, and a dormal cap which is a press fit on the retaining collar and is shaped in order to accommodate and protect the feed dispensing means when it is connected in its operative position.
After each feed it is important that the infant oral feeding bottle component parts should be sterilised, and a wide variety of sterilisers and sterilisation methods have been proposed. The term “sterilisation” for this purpose is used to indicate a certain standard which is generally accepted as being capable of killing the harmful bacteria that might be dangerous to young babies if such bacteria were to come into contact with the feed. This standard is more correctly called “disinfection”. Most of the products and methods which have been proposed, however, are called respectively “sterilisers” and “sterilisation” and this is the term which will henceforth be used in this document.
It is generally accepted that moist heat, steam or water at 80° C. for one minute on the surface of the components of the feeding bottle is sufficient to kill harmful bacteria and to sterilise the bottle components for use.
One method of sterilisation which is commonly used is to use a chemical bath into which the components are totally submerged for at least 30 minutes. This has the disadvantage that it takes a long time, and the recommended time period has to be restarted if further components are added to those already submerged. In addition, all traces of the chemical have to be removed as the chemical is harmful to ingest. For this reason, it is recommended that the bottle components are rinsed in recently boiled water after sterilisation, which can itself give rise to possible to re-infection.
Electrical sterilisers are also commercially available, and typically these can comprise an enclosed container capable of receiving six feeding bottles in disassembled state. A predetermined quantity of water, usually 30 ml or 40 ml is placed on a heater dish and boiled dry. The steam created sterilises the surfaces of all the feeding bottle components. The process takes from five to ten minutes, and is thus quicker than the chemical method, and probably more reliable, but does require a relatively expensive electrical device. The device is considerably more expensive than an electrical kettle, for example.
A further method which has been proposed is to place all of the feeding bottle components into a vessel together with a quantity of water, and to boil the water by placing the container in a microwave oven for a specific period sufficient to create steam within the vessel. The process takes approximately 10 minutes as the bottle components and the vessel itself also absorb heat, thus delaying the rise in temperature of the water.
Other sterilisation methods use a carrier for the feeding bottle components which is placed in a container over a pan of water so that the steam rises into the container as the pan of water is brought to the boil, eventually sterilising all the components. This is a fairly lengthy procedure. Alternatively, all the feeding bottle components are placed in a pan of boiling water and the water kept boiling for some time. If, in this latter method, some of the components are made of plastics that float or contain air bubbles that allow them to float, it cannot be established exactly how long they must stay in the boiling water in order to sterilise them.
As will be seen from the above, all of the known sterilisation methods use either expensive equipment, or potentially harmful chemicals, or take a considerable time to sterilise the components of a feeding bottle.